SDK packages

Android SDK packages can be installed directly from upstream using #Android Studio's SDK Manager or the sdkmanager command line tool (part of the Android SDK Tools). Some Android SDK packages are also available as AUR packages, they generally install to /opt/android-sdk/.

Making /opt/android-sdk group-writeable

The AUR packages install the SDK in /opt/android-sdk/. This directory has root permissions, so keep in mind to run sdk manager as root. If you intend to use it as a regular user, create the Android sdk users group, add your user.

# groupadd android-sdk
# gpasswd -a <user> android-sdk

Set an access control list to let members of the newly created group write into the android-sdk folder. As running sdkmanager can also create new files, set the ACL as default ACL. the X in the default group entry means "allow execution if executable by the owner (or anyone else)"

if you get a message about unresolvable dependencies, install Java manually and try again.

as an alternative, you can install the ADT via eclipse's built in "add new software" command (see instructions on ADT site).

if you are in real trouble, it is also possible to download Android SDK and use the bundled Eclipse. This usually works without problems.

if you need to install extra SDK plugins not found in the AUR, you must change the file ownership of /opt/android-sdk first. You can do this with # chgrp -R users /opt/android-sdk ; chmod -R 0775 /opt/android-sdk (see File Permissions for more details).

Note: If the plugins do not show up in Eclipse after the AUR package has been upgraded, then eclipse probably has out-of-date caches. Running sudo eclipse -clean once should clear them. If the problem persists, uninstall eclipse and all the plugins, delete /usr/share/eclipse, and reinstall everything.

Building

Please note that these instructions are based on the official AOSP build instructions. Other Android-derived systems such as LineageOS will often require extra steps.

This activation is only active for the current terminal session. The virtual env will be kept in the venv folder.

Passing "--system-site-packages" to virtualenv2 points your virtual environment to your installed python2.7 modules. This should give you all python modules you need for the build, assuming you've installed the required dependencies such as python2-mako.

If during the build you still receive errors pertaining to missing python modules a quick and dirty fix might be to symlink /usr/lib/python2.7/* to ~/android/venv/lib/python2.7/ (Change ~/android to reflect your build directory if different than above).

Example:

$ ln -s /usr/lib/python2.7/* ~/android/venv/lib/python2.7/

or (assuming build directory Data/Android_Build):

$ ln -s /usr/lib/python2.7/* /Data/Android_Build/venv/lib/python2.7/

Downloading the source code

This will clone the repositories. You only need to do this the first time you build Android, or if you want to switch branches.

The repo has a -j switch that operates similarly to the one used with make. Since it controls the number of simultaneous downloads, you should adjust the value depending on downstream network bandwidth.

You will need to specify a branch (release of Android) to check out with the -b switch. If you leave the switch out, you will get the so-called master branch.

Note: To further decrease sync times, you can utilize the -c switch with the repo command as such:

$ repo sync -j8 -c

The -c switch will only sync the branch which is specified in the manifest, which in turn is determined by the branch specified with the -b switch, or the default branch set by the repository maintainer.

Wait a long time. Just the uncompiled source code, along with the .repo and .git directories that are used to keep track of it, are well over 10 GB. As of Android 6.0.1, the entire codebase totals 40 GB.

Note: If you want to update your local copy of the Android source, at a later time, simply enter the build directory, load the Virtualenv, and re-sync:

$ repo sync

Building the code

This should do what you need for AOSP:

$ source build/envsetup.sh
$ lunch full-eng
$ make -j4

If you run lunch without arguments, it will ask what build you want to create. Use -j with a number between one and two times number of cores/threads.

The build takes a very long time.

Note:

Make sure you have enough RAM. Android will use the /tmp directory heavily. By default the size of the partition the /tmp folder is mounted on is half the size of your RAM. If it fills up, the build will fail. 4GB of RAM or more is recommended. Alternatively, you can get rid of the tmpfs from fstab all together.

"GNU make can handle parallel tasks with a -jN argument, and it's common to use a number of tasks N that's between 1 and 2 times the number of hardware threads on the computer being used for the build. E.g. on a dual-E5520 machine (2 CPUs, 4 cores per CPU, 2 threads per core), the fastest builds are made with commands between make -j16 and make -j32."

Testing the build

When finished, run/test the final image(s).

$ emulator

Creating a flashable Image

To create an image that can be flashed it is necessary to:

make -j8 updatepackage

This will create a zip image under out/target/product/hammerhead (hammerhead being the device name) that can be flashed.

Flashing

In some cases, you want to return to the stock Android after flashing custom ROMs to your Android mobile device. For flashing instructions of your device, please use XDA forums.

Fastboot

Note: Restoring firmwares using fastboot can be quite tricky, but you might want to browse XDA developers forums for a stock firmware, which is mostly a *.zip file, but inside of it, comes with the firmware files and flash-all.sh script. For example, Google Nexus firmwares include flash-all.sh script or another example could be for OnePlus One - XDA thread, where you can find firmwares with included flash-all.sh script.

Samsung devices

Samsung devices can't be flashed using Fastboot tool. Alternatives are only Heimdall and Odin (by using Windows and VirtualBox).

Heimdall

Heimdall is a cross-platform open-source tool suite used to flash firmware (also known as ROMs) onto Samsung mobile devices and is also known as an alternative to Odin. It can be installed as heimdallAUR.

Open Odin. The white box (a big one at the bottom-left side) named Message, should print a line similar to this:

<ID:0/003> Added!!

which means that your device is visible to Odin & Windows operating system and is ready to be flashed.

Troubleshooting

Android Studio: Android Virtual Devices show 'failed to load'.

Make sure you've exported the variable ANDROID_HOME as explained in #Android Studio.

Android Studio: 'failed to create the SD card'

If you try to run an AVD (Android Virtual Device) under x86_64 Arch and get the error above, install the lib32-gcc-libs package from the multilib repository.

Eclipse: During Debugging "Source not found"

Most probably the debugger wants to step into the Java code. As the source code of Android does not come with the Android SDK, this leads to an error. The best solution is to use step filters to not jump into the Java source code. Step filters are not activated by default. To activate them: Window > Preferences > Java > Debug > Step Filtering.
Consider to select them all. If appropriate you can add the android.* package. See the forum post for more information: http://www.eclipsezone.com/eclipse/forums/t83338.rhtml

Sometimes, beginning to load an AVD will cause an error message similar to this to be displayed, or the loading process will appear to finish but no AVD will load and no error message will be displayed.

The AVD loads an incorrect version of libstdc++, you can remove the folder libstdc++ from ~/.android-sdk/emulator/lib64 (for 64-bit) or ~/.android-sdk/emulator/lib (for 32-bit) , e.g.:

$ rm -r ~/.android-sdk/emulator/lib64/libstdc++

Note that in versions before Android Studio 3.0, this directory was in a different location:

$ rm -r ~/Android/Sdk/emulator/lib64/libstdc++

Alternatively you can set and export ANDROID_EMULATOR_USE_SYSTEM_LIBS in ~/.profile as:

You can try to install glxinfo (mesa-demos) but if your computer has enough power you could simply use software to render graphics. To do so, go to Tools > Android > AVD Manager, edit the AVD (click the pencil icon), then select Software - GLES 2.0 for Emulated Performance > Graphics.

Android Emulator: no keyboard input in xfwm4

In xfwm4, the vertical toolbar buttons window that is on the right of the emulator takes focus from the emulator and consumes keyboard events.
(bug report)